Mottled Umber Geometridae

Erannis defoliaria (Clerck, 1759)

Description: Wingspan 40-45mm. Adult males are generally reddish brown, although this ground colour can vary considerably; some individuals can be much lighter or darker.

Similar Species: The males are similar in appearance to the Dotted Border A. marginaria but lack the dots along the outer margin of the hind wing. The wingless females may be found after dark (by torchlight) on the trunks of trees.

Key Identification Features:

Sets:  male upperside

Flight Period: From the end of September through to mid-February but more commonly encountered in late October and November, however there are occasional records, which extend beyond its normal flight period.

Status: Widespread and frequently encountered in southern counties, scarcer further north, which may be attributed to its late flight period and limited fieldwork especially in northern counties at this time of year.

Ecology: An autumn species inhabiting woodland, bogs and a variety of other habitats. Males come frequently to light in moderate numbers. The larvae can be found from April to June on a variety of trees, particularly oak Quercus spp., birch Betula spp., willow Salix spp.., Hawthorn Crataegus monogyna and Hazel Corylus avellana. It overwinters in the egg stage.

World Distribution: Throughout Europe and Armenia.

Bradley & Fletcher number: 1935 Agassiz number: 70.256

Additional information:

UK Moths account


 Thompson, R. S. & Nelson, B., 2003 (Oct 2). [In] The Butterflies and Moths of Northern Ireland